As humans live longer, what will happen to our memories? Provided our brains stay functional, will the “memory card” be filled? Will old memories have to be “overwritten”?

As a novelist writing about semi-immortals, I’ve been imagining what their centuries-long lives were like and giving them memories, but should I take those memories away from them?

New research creates more questions than answers:

There are only two places in the human brain where cells are created. One is the dentate gyrus of the hippocampus. It’s heavily involved in forming memories. The cells in the dentate gyrus team up with nearby non-replicating cortical cells to form memories so how are new brain cells “wired in?”

Are new neural connections made between old and new cells, or do some old connections move to the new cells?

A new study suggests that the latter is true, new cells steal connections from old ones. So what does all this mean?

Neurogenesis is associated with increased ability to learn new material, but are memories lost in the process? Further, exercise has been known to increase brain cell genesis, so do active people have fewer memories? Is this kind of brain plasticity better than having a less active one?

What does your experience tell you about aging and memory? If you’re loosing memories through neurogenesis, what are you going to do about it?